Current commercial methods for drug or other analyte detection in solutions such as urine primarily involve antibody staining systems attached to Whatman filter paper. Such antibody staining systems are generally targeted to specific analytes. An exemplary use for such a system is to dip the antibody drug detection device into a sample and observe a color change correlating with the presence or absence of the analyte. A difficulty in using these systems is that they often yield negative results. For example, such systems may give a color change when the corresponding analyte is not present. They also do not give a permanent color change.
Molecularly imprinted polymers are polymers that have been traditionally used to filter and purify compounds during production processes. The polymers are formed in the presence of a molecule that is extracted afterwards, thus leaving cavities complementary to the extracted molecule behind. These polymers show a certain chemical affinity for the extracted molecule and thus can be used to fabricate sensors.
Creating a molecularly imprinted polymer that can be used as a biosensor capable of producing a permanent and positive color change for detection of an analyte would fulfill a long held need and be a large improvement over existing antibody-based drug detection systems.